[BUG] BuildStrategy: Cannot Use Context Dir as Working Directory

[adambkaplan]

Is there an existing issue for this?

• [X] I have searched the existing issues

Kubernetes Version

k8s: 1.28.7 Tekton Pipelines: 0.56.2

Shipwright Version

0.12.0

Current Behavior

When authoring a build strategy, builds risk failure if a build strategy step has its workingDir set to a sub-directory and source is cloned from git. Git expects the target directory of any clone action to be empty.

Setting workingDir to a sub-directory of the source root (ex: contextDir) results in errors like the following:

2024/04/11 16:39:28 /usr/bin/git -c safe.directory=/workspace/source clone -h
2024/04/11 16:39:28 /usr/bin/git -c safe.directory=/workspace/source submodule -h
2024/04/11 16:39:28 /usr/bin/git -c safe.directory=/workspace/source clone --quiet --no-tags --single-branch --depth 1 -- https://github.com/redhat-developer-demos/quinoa-wind-turbine.git /workspace/source
2024/04/11 16:39:28 fatal: destination path '/workspace/source' already exists and is not an empty directory. (exit code 128)

Expected Behavior

Ideally build steps succeed if the directory is a subPath of the working directory. However, this may prove difficult due to the way Tekton, Kubernetes, and potentially the underlying container runtime operate (everything runs in a single TaskRun/Pod today).

Steps To Reproduce

1. Create a build strategy that has a step workingDir set to a sub-path of $(params.shp-source-root)
2. Run a Build with this strategy that clones source from git.

Anything else?

This is perhaps something that we document as a known issue - ex: in a guide for Build Strategy authors.